JP6360697B2 - Shaft holding member for shaft enlargement processing - Google Patents

Description

  The present invention relates to a shaft holding member for shaft enlargement processing.

  Shaft enlargement processing is known as one of the processing methods for forming a relatively large diameter portion in the axial middle portion of the shaft material. As an example of the shaft enlargement processing method, axial compression stress is applied to the shaft material. There is known a method of enlarging a part of a shaft material by adding a bending angle in the state and rotating the shaft material, thereby forming a large diameter portion.

  A processing machine that performs the shaft enlargement processing method is typically disposed along a pair of shaft holding members that hold both ends of the shaft material and a reference line on which the shaft material is disposed, and the shaft holding member is fixed. A pair of spindles, and one spindle is moved along the reference line to compress the shaft member in the axial direction, while the other spindle is rotated at an angle with respect to the reference line, and a part of the shaft member is rotated. (For example, refer to Patent Document 1).

  The shaft holding member is worn out by contact with the shaft material, so that the shaft holding member is appropriately replaced. The shaft holding member described in Patent Document 1 includes a case fixed to a spindle and a sleeve press-fitted into the case, and is configured so that only the sleeve can be replaced. Although the sleeve is worn out by contact with the shaft member, the cost can be reduced by replacing only the sleeve.

JP 2013-166168 A

  In the shaft holding member described in Patent Document 1, the sleeve comes into contact with the enlarged portion of the shaft material, and a load acts on the sleeve in a direction opposite to the compression direction of the shaft material as the shaft material is compressed. If the load acting on the sleeve is excessive, the sleeve may move in a direction opposite to the compression direction of the shaft member, causing a positional shift with respect to the case.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to prevent displacement of a sleeve in a shaft holding member including a case and a sleeve inserted into the case.

In a shaft enlargement process that enlarges a part of the shaft material, a shaft holding member that holds the end portion of the shaft material, a cylindrical case fixed to a pressurizing device that applies a shaft compressive stress to the shaft material, A sleeve that is inserted into the case and accommodates an end portion of the shaft member and is in contact with the enlarged portion of the shaft member, and is fitted to the inner peripheral surface of the case and the outer peripheral surface of the sleeve. A shaft holding member configured by an annular concavo-convex portion and provided with an engaging portion that prevents relative movement of the sleeve in a direction opposite to the compression direction of the shaft member.

  ADVANTAGE OF THE INVENTION According to this invention, in the shaft holding member provided with a case and the sleeve inserted in a case, position shift of a sleeve can be prevented.

It is a figure which shows typically an example of the shaft enlargement processing method for demonstrating embodiment of this invention. It is a figure which shows typically the other example of the shaft enlargement processing method for demonstrating embodiment of this invention. It is a figure which shows typically the other example of the shaft enlargement processing method for demonstrating embodiment of this invention. It is a figure which shows typically the other example of the shaft enlargement processing method for demonstrating embodiment of this invention. It is a figure which shows typically the other example of the shaft enlargement processing method for demonstrating embodiment of this invention. It is a side view of an example of the shaft enlargement processing machine which implements the shaft enlargement processing method of FIG. It is sectional drawing of the shaft holding member and spindle of the shaft enlargement processing machine of FIG. It is a figure which shows typically the structure of the shaft holding member of FIG. It is a figure which shows typically the structure of the modification of the shaft holding member of FIG.

  1 to 5 schematically show various examples of a shaft enlargement processing method for explaining an embodiment of the present invention.

  The shaft enlargement processing method shown in FIG. 1 enlarges a part of the shaft material W by rotating the shaft material W by adding a bending angle in a state where axial compression stress is applied to the shaft material W.

  As shown in FIG. 1A, both end portions of the shaft member W are inserted into a pair of shaft holding members 1a and 1b arranged to face each other on the reference line A. Then, both end portions of the shaft member W are in contact with the bottom portions of the shaft holding members 1a and 1b, respectively, and the shaft member W is sandwiched between the pair of shaft holding members 1a and 1b. A predetermined interval D is provided between the pair of shaft holding members 1a and 1b, and the interval D is determined according to the axial length and the outer diameter of the enlarged portion formed in the shaft member W.

  As shown in FIG. 1B, the shaft holding member 1b is translated along the reference line A, and the shaft member W sandwiched between the pair of shaft holding members 1a and 1b is compressed in the axial direction. Then, the shaft holding member 1a is inclined with respect to the reference line A and is rotationally driven, and the shaft member W sandwiched between the pair of shaft holding members 1a and 1b is centered on the bending center O on the reference line A. It is bent and rotated around the axis of the shaft W. As the shaft member W is bent and rotated, an alternating load is applied to the curved portion (intermediate portion) of the shaft member W in the direction intersecting the axial direction of the shaft member W on the inner side and the outer side in the bending direction.

  As shown in FIG. 1C, since the shaft member W is compressed in the axial direction, the inside of the curved portion of the shaft member W swells due to plastic deformation, and the bulge due to plastic deformation extends over the entire circumference. It grows and the curved part of the shaft W is enlarged.

  As shown in FIG. 1D, after the interval between the pair of shaft holding members 1a and 1b reaches the target interval (the axial length of the enlarged portion of the shaft member W), the compression of the shaft member W is stopped, Then, the shaft holding member 1a inclined with respect to the reference line A is disposed again along the reference line A, and the shaft member W is bent back. By the above procedure, the enlargement process for the shaft member W is completed, and the rotation of the shaft member W is stopped.

  Thereafter, as shown in FIG. 1E, the shaft member W is detached from the pair of shaft holding members 1a and 1b.

  The shaft enlargement processing method shown in FIG. 2 is common to the shaft enlargement processing method of FIG. 1 in that an alternating load is applied to the curved portion (intermediate portion) of the shaft member W by bending and rotating around the shaft member W. Instead of tilting the shaft holding member 1a with respect to the reference line A, the shaft member W is bent by sliding the shaft holding member 1a in a direction intersecting the reference line A.

  In the shaft enlargement processing method shown in FIG. 3, the end portion of the shaft member W is rotatably held in an unconstrained state by one shaft holding member 1a, and the end portion of the shaft member W is held by the other shaft holding member 1b. Is held in a restrained state in a non-rotatable manner, and the shaft member W is bent by rotating the shaft holding member 1a and the end of the shaft member W held by the shaft holding member 1a around the reference line A, and An alternating load is applied to the curved portion (intermediate portion) of the material W.

  In the shaft enlargement processing method shown in FIG. 4, the end portions of the shaft member W are held in a non-rotatable restrained state by the shaft holding members 1 a and 1 b, and one shaft holding member 1 a is reciprocated around the reference line A. By rotating, an alternating load is applied to the intermediate part of the shaft member W.

  In the shaft enlargement processing method shown in FIG. 5, in place of the displacement and rotation of the shaft holding members 1 a, 1 b and the shaft material W, bending or torsional vibration is applied to the shaft material W from the vibration generator OSC. An alternating load is applied to the middle part.

  FIG. 6 shows a configuration of an example of a shaft enlargement processing machine that performs the shaft enlargement processing method shown in FIG. 1.

  A shaft enlargement processing machine 10 shown in FIG. 6 includes a pair of shaft holding members 11 that hold the end portions of the shaft material, and a pair of holder units that are spaced apart from each other along a reference line A on which the shaft material is disposed. 12a, 12b. One holder unit 12a is supported by the base 13 so as to be tiltable with respect to the reference line A, and the other holder unit 12b is supported by the base 13 so as to be movable along the reference line A. Yes.

  The holder units 12a and 12b include a spindle 14 on which the shaft holding member 11 is mounted, a housing 15 that rotatably supports the spindle 14, and an end portion of the shaft member inserted into the shaft holding member 11 from the shaft holding member 11. The cylinders 16 for extruding are respectively included, and the spindles 14 of the holder units 12a and 12b are arranged on the reference line A.

  The shaft enlargement processing machine 10 includes a translation drive unit 17 that moves the holder unit 12b along the reference line A, a tilting unit 18 that tilts the holder unit 12a with respect to the reference line A, and a spindle 14 of the holder unit 12a. And a rotation drive unit 19 that rotationally drives the motor. The holder unit 12a, 12b and the translation drive unit 17 constitute a pressurizing device that compresses the shaft material in the axial direction, and the holder units 12a, 12b, the tilting unit 18, and the rotation drive unit 19 are arranged in the middle part of the shaft material. A load generator that applies an alternating load in a direction intersecting the axial direction (reference line A) of the shaft member is configured.

  FIG. 7 shows the configuration of the shaft holding member 11 and the spindle 14.

  The spindle 14 is provided with a fitting hole 20 into which the shaft holding member 11 is inserted, and a pin insertion hole 21 connected to the fitting hole 20. A pressure receiving plate 22 that receives the shaft holding member 11 is inserted into the fitting hole 20, and the pressure receiving plate 22 is abutted against and fixed to a step 23 formed inside the fitting hole 20. The pin insertion hole 21 is provided through the spindle 14 along the central axis (reference line A) of the spindle 14, and the knock pin 24 of the cylinder 16 (see FIG. 6) is inserted into the pin insertion hole 21. ing.

  The shaft holding member 11 includes a cylindrical case 30, a sleeve 31 inserted into the case 30, and a metal brace 32 inserted into the sleeve 31. The case 30 is inserted into the fitting hole 20 of the spindle 14, and the rear end face of the case 30 and the sleeve 31 inserted into the case 30 is supported by the pressure receiving plate 22. Then, the step 33 provided on the outer peripheral surface of the case 30 is pressed by the flange pipe 34 fastened to the opening end portion of the spindle 14 where the fitting hole 20 is opened, and the case 30 is fixed to the spindle 14. . The sleeve 31 accommodates the end portion of the shaft member W. The gold 32 constitutes the bottom of the shaft holding member 11, is supported by the knock pin 24, receives the end surface of the shaft member W, is pressed by the knock pin 24, and is inserted into the shaft holding member 11. The part is pushed out from the shaft holding member 11.

  The sleeve 31 receives the reaction force of the alternating load applied to the shaft member W, and a relatively large load acts particularly on the surface 30 a of the opening of the sleeve 31. Therefore, the sleeve 31 is worn out by repeated use. The sleeve 31 inserted into the case 30 can be removed from the case 30, and only the sleeve 31 can be replaced according to wear.

  The sleeve 31 is in contact with the enlarged portion of the shaft member in the shaft enlargement process, and a load acts on the sleeve 31 in a direction opposite to the compression direction of the shaft member W as the shaft member W is compressed. The case 30 and the sleeve 31 are provided with an engaging portion that prevents the shaft 30 from being moved in the direction opposite to the compression direction against the load.

  FIG. 8 shows an example of the engaging portion provided in the case 30 and the sleeve 31.

  An annular uneven portion 40 is provided on the inner peripheral surface of the case 30, and an annular uneven portion 41 that is engaged with the uneven portion 40 of the case 30 is provided on the outer peripheral surface of the sleeve 31. Engagement of the concave and convex portions 40 and 41 of the case 30 and the sleeve 31 prevents the sleeve 31 from being moved in the direction opposite to the compression direction of the shaft member even by the load acting on the sleeve 31. .

  It is preferable that the depth D of each concave portion and the height H of the convex portions of the concave and convex portions 40 and 41 are 50 μm or more and 1% or less of the outer diameter of the sleeve 31. According to this, it is possible to obtain an engagement force larger than the friction caused by press-fitting in a typical surface roughness of the case 30 and the sleeve 31, and the movement of the sleeve 31 in the direction opposite to the compression direction of the shaft member can be further increased. It becomes possible to prevent it reliably.

  In the above configuration, the sleeve 31 is inserted into the case 30 by shrink fitting, for example. In the illustrated example, both the case 30 and the sleeve 31 are provided with a plurality of concave portions and convex portions in the concave and convex portions 40 and 41. However, at least a pair of concave portions and convex portions may be provided.

  FIG. 9 shows another example of the engaging portion provided in the case 30 and the sleeve 31.

  In the example shown in FIG. 9, the central axis (reference line) of the case 30 and the sleeve 31 as the individual concave portions and convex portions of the concave and convex portions 40 and 41 of the case 30 and the sleeve 31 go in the direction opposite to the compression direction of the shaft material. It is formed in a saw blade shape spaced apart from A). The inner peripheral surface of the case 30 and the outer peripheral surface of the sleeve 31 are formed in a tapered shape that is separated from the reference line A in the direction opposite to the compression direction of the shaft member.

  According to this example, the sleeve 31 can be inserted into the case 30 by press-fitting, and the sleeve 31 can be easily inserted into the case 30.

  Here, the sleeve 31 is worn by contact with the shaft member W, but in order to suppress the wear of the sleeve 31, it is preferable to use a hard material as the material of the sleeve 31. By suppressing the wear of the sleeve 31, the replacement frequency of the sleeve 31 can be lowered.

  As a base material for forming the sleeve 31, a material having a Rockwell hardness (JIS G 0202) of HRC58 or higher can be suitably used. Examples thereof include die steel such as SKD11, high-speed steel such as SKH51, and semi-high-speed steel. can do.

  Further, from the viewpoint of suppressing the wear of the sleeve 31, the sleeve 31 may be subjected to a surface hardening treatment. When the surface hardening treatment is performed, the surface property is preferably Vickers hardness (JIS Z 2244) HV1200 or more, HV3000 or more is more preferable, and smoothness is preferable. Examples of such surface hardening treatment include film formation such as vanadium-based film, chromium-based film, titanium-based film, and DLC (diamond-like carbon) film, nitriding treatment, and the like.

  The surface hardening treatment may be performed on at least the surface 31a of the opening of the sleeve 31, and may be performed on the entire inner peripheral surface of the sleeve 31 including the surface 31a of the opening, or may be performed on the entire surface of the sleeve 31. Also good.

  When forming a film as the surface hardening treatment, the film may be composed of a single layer film of the various films listed above or may be composed of one or more multilayer films. Examples of the film forming method include salt bath immersion (thermal reaction deposition diffusion method), CVD (chemical vapor deposition method), PVD (physical vapor deposition method), PCVD (plasma CVD method), and the like. it can.

  The shaft enlargement processing machine 10 that performs the shaft enlargement processing method shown in FIG. 1 has been described above as an example of the shaft holding member of the present invention, but the shaft enlargement processing method shown in FIGS. 2 to 5 is performed. The shaft enlargement processing machine differs only in the operation method of the holder unit and spindle for applying an alternating load to the intermediate part of the shaft material, and the configuration of the shaft holding member described above can also be applied to these shaft enlargement processing machines It is.

  Next, various production examples of the sleeve 31 described above and life evaluation thereof will be described.

  The sleeve of Production Example 1 uses semi-high-speed steel as a base material and omits the surface hardening treatment. The sleeve of Production Example 2 uses semi-high-speed steel as a base material and is subjected to nitriding as a surface hardening treatment. The sleeve of Production Example 3 has SKH51 (high-speed steel) as a base material and a VC (vanadium carbide) film formed by a TD process (registered trademark) which is a kind of salt bath immersion method as a surface hardening treatment. Table 1 shows the base material hardness and surface properties of the sleeves of Preparation Examples 1 to 3.

  For each of the sleeves of Production Examples 1 to 3, the shaft enlargement machine 10 is repeatedly subjected to shaft enlargement processing under the same conditions, and the service life is increased by the number of machining until visible galling (adhesion wear) occurs. evaluated. The evaluation results are shown in Table 1. From the evaluation results shown in Table 1, it can be seen that the wear of the sleeve due to contact with the shaft can be suppressed by performing the surface hardening treatment.

  As described above, the following items are disclosed in this specification.

(1) In a shaft enlargement process for enlarging a part of a shaft material, a shaft holding member for holding an end portion of the shaft material, which is fixed to a pressurizing device that applies a shaft compressive stress to the shaft material. A case and a sleeve that is inserted into the case and accommodates an end portion of the shaft member and is in contact with an enlarged portion of the shaft member. The case and the sleeve have a compression direction of the shaft member. A shaft holding member provided with an engaging portion that prevents relative movement of the sleeve in the opposite direction.
(2) The shaft holding member according to (1), wherein the engaging portion is provided on an inner peripheral surface of the case and an outer peripheral surface of the sleeve.
(3) The shaft holding member according to (2), wherein the engaging portion is configured as an annular uneven portion.
(4) The shaft holding member according to (3), wherein each of the concave portions and the convex portions of the engaging portion moves away from the central axis of the case and the sleeve as it goes in a direction opposite to the compression direction of the shaft member A shaft holding member formed in the shape of a saw blade that is spaced apart.
(5) The shaft holding member according to (4), wherein an inner peripheral surface of the case and an outer peripheral surface of the sleeve are arranged in a direction opposite to a compression direction of the shaft member and a central axis of the case and the sleeve. The shaft holding member formed in the taper shape spaced apart from.
(6) The shaft holding member according to any one of (3) to (5) above, wherein the depth of each concave portion and the height of the convex portion of the engaging portion are 50 μm or more and the outside of the sleeve. A shaft holding member that is 1% or less of the diameter.
(7) The shaft holding member according to any one of (1) to (6), wherein in the sleeve, at least a surface of an opening portion into which an end portion of the shaft member is inserted is subjected to surface hardening treatment. A shaft holding member.
(8) The shaft holding member according to (7), wherein the surface-hardened sleeve has a Vickers hardness of HV1200 or more.

DESCRIPTION OF SYMBOLS 1a Shaft holding member 10 Shaft enlargement processing machine 11 Shaft holding member 12a Holder unit 12b Holder unit 13 Base 14 Spindle 15 Housing 16 Cylinder 17 Translation drive part 18 Tilt part 19 Rotation drive part 20 Fitting hole 30 Case 31 Sleeve 32 Gold 40 Concavity and convexity (engagement part)
41 Concavity and convexity (engagement part)
A Reference line W Shaft material

Claims (6)

In shaft enlargement processing to enlarge a part of the shaft material, a shaft holding member that holds the end of the shaft material,
A cylindrical case fixed to a pressurizing device that applies axial compressive stress to the shaft member;
A sleeve that is inserted into the case, accommodates an end portion of the shaft member, and contacts the enlarged portion of the shaft member;
With
The inner peripheral surface of the case and the outer peripheral surface of the sleeve are configured by annular concavo-convex portions that fit together, and an engagement portion that prevents relative movement of the sleeve in a direction opposite to the compression direction of the shaft member. A shaft holding member provided with The shaft holding member according to claim 1 ,
A shaft holding member in which the individual recesses and projections of the engaging portion are formed in a saw blade shape that is separated from the central axis of the case and the sleeve as it goes in a direction opposite to the compression direction of the shaft member. The shaft holding member according to claim 2 ,
A shaft holding member in which an inner peripheral surface of the case and an outer peripheral surface of the sleeve are formed in a tapered shape that is separated from a central axis of the case and the sleeve as going in a direction opposite to a compression direction of the shaft member. The shaft holding member according to any one of claims 1 to 3 ,
The shaft holding member, wherein the depth of each concave portion and the height of the convex portion of the engaging portion is 50 μm or more and 1% or less of the outer diameter of the sleeve. The shaft holding member according to any one of claims 1 to 4 ,
The shaft holding member in which the surface hardening process is given to the surface of the opening part in which the edge part of a shaft material is inserted in the said sleeve at least. The shaft holding member according to claim 5 ,
A shaft holding member whose surface has a Vickers hardness of HV1200 or more.

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